As such a type of vibration damping device, a constitution that includes: a first mounting member that is coupled to any one of the vibration generating part and the vibration receiving part and has a tubular shape, and a second mounting member that is coupled to the other; an elastic body that elastically couples the mounting members; and a partition member that partitions a liquid chamber, which is inside the first mounting member and is sealed with a liquid, into a main liquid chamber and an auxiliary liquid chamber is known. The partition member is formed with a restricted passageway that causes the main liquid chamber and the auxiliary liquid chamber to communicate with each other. In the vibration damping device, when vibrations are input, the mounting members are displaced relative to each other while elastically deforming the elastic body, and a liquid pressure of the main liquid chamber is changed. A liquid circulates through the restricted passageway. Thereby, the vibrations are absorbed and damped.
Meanwhile, in the vibration damping device, after a large load (vibration) is input from, for instance, irregularities of a road surface, and the liquid pressure of the main liquid chamber is abruptly raised, when the load is input in a reverse direction by rebound or the like of the elastic body, the main liquid chamber may undergo abrupt conversion into negative pressure. Then, due to the conversion into negative pressure, cavitation by which numerous air bubbles are generated in the liquid is caused. Furthermore, due to cavitation collapse in which the generated air bubbles collapse, abnormal sound may occur.
Therefore, like the vibration damping device disclosed in, for instance, Patent Document 1 below, a constitution in which a valve body is provided in the restricted passageway, and thereby conversion of the main liquid chamber into the negative pressure is suppressed even when vibration having a large amplitude is input is known.